In motor vehicles having automated manual transmissions or automatic transmissions, even if the accelerator is not actuated by the driver, drive is transmitted from a prime mover of the motor vehicle to the drive axle(s) of the motor vehicle, which then results in a forward motion even though the accelerator is not actuated. To make the motor vehicle stop, the driver must actively operate the relevant service brake, which results in the prime mover working against the service brake and thus higher fuel consumption.
To prevent increased fuel consumption, it is known in motor vehicles to selectively disconnect a connection between the prime mover and the drive axle(s) of the motor vehicle as part of that function and thus deliberately suppress the forward movement of the motor vehicle. The activation and deactivation of the function occurs depending on the actuation of the service brake. A sensor detects the actuation or release of the service brake by means of an adjustment travel of an operating element of the service brake. Upon actuation of the service brake, the sensor responds after a short adjustment travel of the actuating element to signal a braking process at an early stage. Releasing the service brake thus does not lead immediately to the deactivation of the function, such that the motor vehicle that is in an inclined position can be set in forward or backward motion, depending on the slope.
From DE 601 18 830 T2 a method is known in which a connection between a prime mover of a motor vehicle and a drive axle of the motor vehicle is disconnected as part of a function. The function is activated if the motor vehicle is stationary and actuation of the service brake is detected by a sensor. An additional slope sensor detects whether the motor vehicle is in an inclined position at that time. Depending on the slope and the selected direction of travel, the function is activated or deactivated. In the presence of a slope exceeding a certain value, the function is not activated, that is, the drive train of the motor vehicle is not placed in a neutral state, in which the prime mover and the drive axle are disconnected from each other, although the motor vehicle is held in a stationary state by the actuated service brake.